The purpose of this study is to evaluate the tolerability and effectiveness of intravenous fructose diphosphate (FDP) in patients in acute sickle cell crisis. FDP provides 4 moles of ATP to the cell for every molecule of glucose that is anaerobically metabolized. It is felt that the increased available energy will help the red blood cell resist sickling and as a result shorten the duration of the pain crisis. The GCRC is requested for infusions of the study drug or placebo every 6 hours over 72 hours. There will be a total of 96 patients evaluated over 4 study centers. The primary hypothesis will focus on the reduction of pain at 24 hours after the first infusion. The study is ongoing. There are no results to report at this time.